Even though Wang has become a successful photographer, he has never lost his respect for junk collectors, who are prominently featured in Wang's work. He says they are an important part of society, and by sorting through and recycling items in a landfill, they reduce the amount of trash. But he admits that it wasn't easy to photograph them at first.

"They have their own life," he says. "Most of them had never had their photo taken before."

Eventually they accepted him and he took many photographs of the children who were born and grew up in trash heaps. In the end, he gave them more than 100 photos as gifts.

"I am happy to help them record their lives," he says.

While photographing the garbage sites around Beijing, Wang also filmed them. A documentary was shown to a small group of people in Beijing in early April. A 200-seat theater was filled, with Wang's friends and people from media organizations spilling out into the aisles.

In order to ensure the audience's safety, the theater manager decided to show it again.

"I am glad to see that my work has been appreciated by so many people in China now," Wang says.

After the premiere, Wang was invited by the University of California, Berkeley, to talk with American scholars who specialize in Asian trash studies. One professor gave a speech on how China has dealt with trash over the years, including the development of China's current refuse disposal system, first introduced in 1949.

During his 10-day trip, Wang looked inside about 10 garbage bins along the streets of Berkeley, took the trash out of the bins and photographed it. A 50-year-old woman told him not to worry, because "someone will come to take care of the trash and they will get it sorted out and recycled".

The following day he visited a sanitation transfer station, where he was told that many of the recyclable items are sent to other countries, including China.

While China is following Western countries to promote sorting recyclable materials, Wang plans to visit many cities to photograph dumped papers, shoes, tires and plastic products from overseas.

"I am sure if the sorted items were good or no harm for the environment, they (the Americans) would keep it in their home country," Wang says. In his opinion, sorting recyclable materials and sending it away is a joke rather than a solution for China.

He said just because trash isn't in plain sight, doesn't mean it doesn't exist. "Where do we want to transport our garbage?"

Another popular way to dispose of garbage in China is to burn it. Wang takes issue with this as well since he believes in the idea of conservation of matter, that matter is neither created nor destroyed during any physical or chemical change.

When he was working on his documentary, Wang saw many unused products in garbage sites, such as millions of packets of instant coffee.

A strong odor surrounded him as the trash burned, releasing dioxins into the air. The pollutants are harmful to people and the environment.

Wang believes people should make the best use of all items. "None of the producers meant to make products only for burning, and the damage for the environment could be bigger than the cost of burning them."

The criticism toward sorting and sending away recyclable materials and trash burning finally lead Wang to focus on the ever-growing consumerism in China.

Wang has taken many pictures of supermarkets, with shelves filled with items wrapped in packing materials. Under the plastic, the food looks fresh and clean.

"Do we have to pack a seven-day-old product that won't disintegrate for 200 years?"

When most Chinese environmentalists are calling for a garbage recycling system, Wang says the answer may lie in consumerism, the focus of his next documentary. He wants to make people think before they purchase products.

"Even though you have to buy a bottle of milk, you can still choose not to pick the most packed one."